New light on vi­ta­min D

LONDON: Women with low lev­els of vi­ta­min D are nearly 50% more likely to de­velop mul­ti­ple scle­ro­sis than those who get enough, ac­cord­ing to a study. The find­ings could help to ex­plain why there are higher rates of the dis­ease among those in the north, who get less sun­light, which helps the body make vi­ta­min D.

It is be­lieved the “sun­shine vi­ta­min”, also found in eggs, red meat and oily fish, may help sup­press im­mune cells that at­tack the body to cause MS. The dis­ease can leave peo­ple wheel­chair-bound by se­verely dam­ag­ing their mus­cles.

US re­searchers at Har­vard TH Chan School of Pub­lic Health in Bos­ton ex­am­ined blood sam­ples from more than 3 200 women, who are two to three times more likely to be di­ag­nosed with MS than men. Those de­fi­cient in vi­ta­min D had a 43% higher chance of get­ting MS than women with ad­e­quate lev­els. The risk was 27% higher for those de­fi­cient in vi­ta­min D as com­pared with those with just in­suf­fi­cient lev­els.

Lead au­thor Dr Kas­san­dra Munger said: “We do know there is a higher in­ci­dence of MS in more north­ern coun­tries, the fur­ther you move away from the equa­tor. One hy­poth­e­sis is that these pop­u­la­tions have a lack of vi­ta­min D due to a lack of sun ex­po­sure.

“Our study adds to the ev­i­dence that vi­ta­min D de­fi­ciency is a risk fac­tor for MS and that cor­rect­ing this in women of re­pro­duc­tive age may re­duce their risk of de­vel­op­ing it. Peo­ple should dis­cuss with their doc­tor whether they need a sup­ple­ment,” she said. Of­fice work­ers, preg­nant women and the el­derly are among those said to be at risk of fall­ing dan­ger­ously low on vi­ta­min D.

The sun­shine vi­ta­min is mea­sured in nanomoles, and peo­ple are de­fi­cient if they have less than 30 nanomoles per litre of blood. This can be raised to ad­e­quate lev­els of 50 nanomoles with a daily tablet. The Amer­i­can study, pub­lished in the jour­nal Neu­rol­ogy, used blood sam­ples from women in Fin­land.

Munger said more re­search was needed, “but striv­ing to achieve vi­ta­min D suf­fi­ciency over the course of a per­son’s life will likely have mul­ti­ple health ben­e­fits”. Dr David Sch­ley, of the MS So­ci­ety, said the study showed that vi­ta­min D re­mained a cru­cial area of re­search. – Daily Mail